TITLE:   GCN CIRCULAR
NUMBER:  43965
SUBJECT: GRB 260312A: Swift detection of a burst
DATE:    26/03/12 03:17:24 GMT
FROM:    David Palmer at LANL <palmer@lanl.gov>

N. J. Klingler (GSFC/UMBC/CRESSTII), C. Gronwall (PSU),
R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), M. J. Moss (GSFC),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 02:57:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 260312A (trigger=1500106).  Swift did not slew.
The BAT on-board calculated location is 
RA, Dec 351.609, -3.533 which is 
   RA(J2000) = 23h 26m 26s
   Dec(J2000) = -03d 31' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 30 sec.  The peak count rate
was ~500 counts/sec (15-350 keV), at ~0 sec after the trigger.

Swift automatic follow-up slews are currently disabled. Thus there
will be no XRT or UVOT data for this trigger, which is also Sun
constrained.

Although Swift could not slew to confirm the GRB with an X-ray
afterglow, the high significance in the BAT image (9.4 sigma)
gives us confidence that this is an astrophysical source.

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)